An area under surveillance often includes more than one camera to cover different locations. Different cameras have different inherent levels of brightness and different locations have different levels of illumination, thereby making the same object (e.g., person or vehicle) appear brighter in one image from one camera than in another image from another camera. Because the same object appears brighter in one image than another, re-identification of an object has been difficult. Re-identification refers to identifying that an object imaged by one camera is the same as an object imaged by another camera. Known re-identification approaches adjust for brightness from one camera to the next camera by averaging equally weighted transfer functions or by determining a transfer function based on equally weighted observations.